Feed roll sensor for edger saw

ABSTRACT

A sensing means for setting spacing between edger feed rolls in accordance with depth of cant passing through edger. Hinged shoe before infeed roll is rotated by cant leading edge, shoe actuating hydraulic servo device coupled to spaced infeed roll pair. Servo device adjusts pressure and spacing between infeed roll pairs, as determined by shoe movement. Outfeed roll pairs are coupled to infeed roll pairs for adjustment to similar spacing and pressure.

United States Patent [191 11] 3,742,992 McMillan July 3, 1973 FEED ROLL SENSOR FOR EDGER SAW [76] Inventor: James R. McMillan, Box 17, Lone f' Exam" 'er Andrew Juhasz Butte British Columbia Canada Assistant Examiner-James F. Coan Attorney-Brian J. Wood [22] Filed: May 5, 1971 Appl. No.: 140,550

Foreign Application Priority Data May 6, I970 Great Britain 2i,703/70 US. Cl 144/246 R B27b 25/02 Field of Search 144/246 G, 242 C,

144/246 R, 246 D; 143/55, 55 A, 55 B, 56

References Cited FOREIGN PATENTS OR APPLICATIONS l/1958 Great Britain 144/246 G [57] ABSTRACT A sensing means for setting spacing between edger feed rolls in accordance with depth of cant passing through edger. Hinged shoe before infeed roll is rotated by cant leading edge, shoe actuating hydraulic servo device coupled to spaced infeed roll pair. Servo device adjusts pressure and spacing between infeed roll pairs, as determined by shoe movement. Outfeed roll pairs are coupled to infeed roll pairs for adjustment to similar spacing and pressure.

6 Claims, 1 Drawing Figure 1 FEED ROLL SENSOR FOR EDGER SAW BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to improvements in sawmill machinery, and more particularly to an edger having means responsive to depth of a cant about to enter between infeed roll pairs sensing the depth and setting the infeed rolls and outfeed roll pairs accordingly; the infeed roll pairs driving the cant to a circular saw of the edger.

Nomenclature Terminology as below listed is used herein.

Flitch A timber with parallel sawn top and bottom surfaces and waney edges.

Cant A sawn timber produced for instance by removing the waney edges from a flitch, the cant being re-sawn to produce dimensioned stock.

2. Prior Art In a gang edger a cant of particular depth passing through the edger is often followed, substantially butt to butt, by a cant of a different depth. This requires adjustment, ordinarily manual, of feed roll pairs of the edger according to the depth.

SUMMARY OF THE INVENTION The present invention contemplates a sensor, being means responsive to depth of a cant about to enter between infeed roll pairs, the sensor being constructed and arranged to set the infeed roll pairs and outfeed roll pairs at a spacing according to the depth of the cant and to develop a required pressure. A shoe is lifted by the cant passing therebeneath prior to entering between a feed roll pair. A link from the shoe activates hydraulic means spacing an upper feed roll of the pair from a lower roll, the spacing being in accordance with depth of the cant.

DESCRIPTION OF THE DRAWINGS The drawing is a simplified diagrammatic elevation showing means responsive to depth of a cant to sense the depth and to effect spacing and pressure between feed roll pairs according to the depth.

SENSOR Apparatus illustrated diagrammatically in the drawing includes means responsive to depth of a cant about to enter between feed roll pairs feeding the cant to a circular saw, constructed and arranged to set spacing between upper and lower rolls of a feed roll pair at a spacing in accordance with the depth of the cant.

Apparatus generally 310 has a first feed roll pair having lower and upper rolls 311 and 312, and a second feed roll pair having lower and upper feed rolls 313 and 314 of a feed roll assembly. A cant 315, having a depth D defined between parallel upper and lower faces 316 and 317, travels through the feed rolls in a direction shown by an arrow 318 to a circular saw 319.

The means responsive as aforesaid to the depth of the cant includes a sensor assembly generally 320 having a shoe 321 with an upturned inner end 322, the shoe being inclined at an acute angle to the upper face 316 (as shown) to facilitate entry of the cant beneath the shoe.

Intermediate rolls 323 and 324 adjacent to the saw as shown are provided to support the cant which,'travelling in the direction of the arrow 318 through the saw,

passes between lower and upper outfeed 325, 326 rolls of the first outfeed roll pair, and lower and upper rolls 327 and 328 of a second outfeed roll pair. The lower rolls and the intermediate rolls are rotatable of fixed horizontal axes, upper sides of these rolls being coplanar and in contact with the lower face 317 of the cant, an upper surface 329 of an infeed support means 330 is also in a fixed position and is coplanar with the lower face of the cant, which bears against the upper surface 319.

The upper roll 312 of the first feed roll pair is mounted on a shaft journalled in a bracket of a yoke 332 rotatable of a shaft 333 of a mount 334. The upper roll 314 of the second feed roll pair is similarly mounted on a yoke 335 rotatable of the shaft 333, with compression springs 336 and 337 urging the yokes to rotate moving the upper rolls downward of the mount 334, the downward motion being limited by means not shown. A U-bracket 338 of the mount carries a shaft 339 upon which an inner end of an arm 341 is journalled, an outer end of the arm being journalled about a fixed shaft 342. Thus rotation of the arm clockwise as viewed in the drawing reduces spacing between the upper and lower infeed rolls, and rotation counterclockwise increases spacing the cant not yet having entered between the infeed rolls.

A hydraulic means generally 343 has a lower end 344 journalled as seen at 345 in the arm 341 between the fixed shaft 342 and the mount U-bracket 338. An upper end 346 of the hydraulic means is journalled in a fixed bracket 347 as shown.

Use of known hydraulic means is contemplated, a Vickers hydraulic power steering device manufactured by Vickers Incorporated and obtainable through ordinary trade sources is illustrated. The shoe 321 has an outer end remote from the upturned inner end 322, the outer end being hinged, as seen at 348, to a frame of theedger, so that entry of the cant rotates the shoe about the hinge according to the depth of the cant.

The shoe has a central bracket 349 from which a link 350 extends upwards to a servo rod 351 adjacent the lower end of the hydraulic means 343. Before the cant travelling in the direction of the arrow 318 has reached a broken outline position indicated at 352 beneath the upturned inner end 322 of the shoe, the shoe 321 is urged by weight of the sensor assembly 320 towards the upper surface 329 of the infeed support means so that, in the absence of a cant, the upturned inner end rests against the upper surface 329, in which position the upper infeed rolls are at minimum spacing from the lower infeed rolls as later becomes apparent.

As the leading edge of the cant, indicated in broken outline at 352, travelling in a direction of the arrow 318 passes beneath the upturned end 322 of the shoe it moves upwards a discrete distance, namely the distance D. This moves the servo rod 351 accordingly (but through a lesser distance) the hydraulic means 343 being constructed and arranged to the rotate the arm 341 counterclockwise through a discrete distance depending upon the distance D. The upper infeed roll 312 is now in a broken outline position 353 with the compression spring 336 extended. As the cant continues to move in the direction of the arrow 318 the leading edge passes between the lower and upper rolls of the first infeed roll pair urging the upper roll from the broken outline position 353 to the fullline position 312.-Movement of the upper feed roll from the broken outline position to the full outline position compresses the spring 336 but, because of the action of the hydraulic means 343, this does not move the mount 334.

So far as mechanism associated with the mount 334 has been described, with the leading edge of the cant between the first and second infeed roll pairs, the mount would have rotated about the shaft 339. A link 354 is pin jointed to an upper end of the U-bracket 338 as shown, with an outer end of the link pin jointed as seen at 355 to a fixed bracket. With the link 354 being parallel to the arm 341, a parallel motion is defined so that the mount 334 remains horizontal notwithstanding the cant has not yet passed between the rolls of the second infeed roll pair. The compression spring 336 of such a strength that movement of the upper infeed roll 312 from its broken outline position to its full line position provides adequate pressure to feed the cant.

Since optimum pressure depends upon a number of parameters some of which are, or can be independent of D, adjustment means 356 are provided to alter the length of the link 350. 7

It is thus seen that entering of the cant beneath th upturned inner end of the shoe senses depth D of the cant, which information is passed by the linkage 350 to the hydraulic means 343 so as to set the infeed roll pairs for spacing and pressure according to the depth D.

The first and second outfeed roll pairs are mounted on an outfeed roll assembly generally 360 essentially as described with reference to the first and second infeed roll pairs. The assembly 360 includes means, not shown, adapted for the upper rolls 326 and 328 normally to be urged towards the lower rolls 325, 327 so that, before the cant has passed beneath the upturned inner end 322 of the shoe 321, the outfeed roll pairs are at a minimum spacing.

Means are provided to transfer motion of the upper rolls of the infeed roll pairs to the upper outfeed roll pairs so that they too are spaced according to the depth of cant D as sensed by the means responsive to entry of the cant as aforesaid. One means of effecting transfer is designated generally 361 and includes an infeed pulley 362, an outfeed pulley 363, with a cable 364 passing over the pulleys as shown, one end of the cable being connected as seen at 365 to an extension of the arm 341, an opposite end 366 of the cable being secured to an arm 367 of the outfeed roll assembly 360, the arm being a counterpart of the arm 341 associated with the infeed roll pairs.

It is seen that rotation of the arm 341 counterclockwise by entry of the cant, as explained, causes the cable 364 to move in a direction indicated by arrows 368 so that the arm 367 is caused to rotate so as to space the outfeed roll pairs according to the spacing of the infeed roll pairs. Means urging the outfeed rolls together have a strength, taking into consideration tension in the cable 364, sufficient to supply force to drive the lumber through the outfeed roll pairs. Effectively, as seen by the lumber passing between the outfeed rolls, the assembly 360 is fixed, pressure being applied by compression of the springs as the springs of the infeed roll pairs. Note that ample power is available from the Vickers hydraulic power steering means, available models having thrust capacity from i ,500 pounds to 5,000 pounds.

Equivalent transfer means can be used, some of which are indicated later in the present disclosure the particular transfer means used not being of importance.

OPERATION Operation has been described for a cant entering beneath the shoe.

Typically, speed of travel of the cant is 4 fps, the upturned inner end 322 of the shoe is spaced forward of the first infeed roll pair by, typically, l0 inches and can be made less thus leading edge 352 travels from the broken line position to a position of engagement by the first feed roll pair in a few hundred milliseconds. When, for example, a 6 inch cant is followed by a 12 inch cant without material time interval as can be required, it is seen that pressure between the first infeed roll pair is reduced after entry of the leading edge of the 12 inch cant beneath the upturned inner end of the shoe. However, if the two cants actually butt one another it is some 330 milliseconds only before the leading edge of the 12 inch cant reaches the first infeed roll pair. Servo action of the hydraulic means 343 is not instantaneous, there is some delay. While additional delay can deliberately be introduced, in practice difficulty is not encountered in the first infeed roll pairs by passage of cants of greater or of less depth D in succession.

As to the outfeed roll pairs, while there is delay in the servo, and further delay inherent in the means 361, nevertheless pressure at the outfeed rolls changes several seconds ahead of actual requirement. Mechanical, or other, delay can be built into the means 361, however, the pressure required at the outfeed rolls can be varied within relatively wide limits without impairment of function thus, in practice, such a delay is not necessary. It is pointed out that the outfeed rolls essentially onlydeal with disposal of a sawn cant and are not required to provide power to drive the cant through the saw, nor to provide restraint to effect alignment. Consequently, these rolls ordinarly operate at less pressure than the infeed rolls and, as before stated, as a practical matter no material difficulty ordinarily arises.

ALTERNATIVE TRANSFER MEANS Alternatively to the means 361, the hydraulic means 343 can be duplicated for the outfeed rolls with simple mechanical linkage between the two hydraulic means. This solution while practical operationally is expensive. Suitable hydraulic servo means, for instance, according to U.S. Pat. No. 3,496,833 can be adapted for the instant purposes. Mechanical linkages employing one or more four-bar mechanisms (not illustrated) can be used with resilient means applying force to rotate the arm 367.

THE embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. In an edger having a feed roll pair feeding a cant to a circular saw, the feed roll pair including an upper and a lower roll, sensor means responsive to depth of a cant about to enter between the upper and lower rolls constructed and arranged to set spacing between the rolls by accordance with the depth of the cant, the sensor including a. a shoe 321 normally urged towards an infeed support means 329 and having an outer end hinged to a frame of the edger so that passage of the cant beneath the shoe swings the shoe about the hinge,

b. hydraulic means 343 having an upper end 346 joumalled in a fixed bracket 347 and a servo rod 351,

c. a link 350 extending from the shoe to the servo rod,

(1. a lower end 344 of the hydraulic means being journalled in an arm 341 the arm having an outer end journalled on a fixed shaft 342 and an inner end joumalled to a mount 334 of the upper roll, the lower roll being mounted rotatable of a fixed axis positioned so that an upper surface of the roll is coplanar of the horizontal plane containing the support surface 329 constructed and arranged so that passage of the cant beneath the shoe, swinging the shoe as aforesaid, moves the servo rod activating the hydraulic means retracting the lower end so as to space the upper roll from the lower roll a distance according to the depth of the cant,

2. Structure as defined in claim 1, the shoe having an upturned inner end 322 and being inclined at an acute angle to an upper surface of the cant so as to facilitate entry of the cant beneath the shoe.

3. Structure as defined in claim 2, the upper roll mount including a compression spring 336 urging the upper roll downwards against the cant with a pressure determined by the depth of the cant.

4. Structure as defined in claim 3, the link 350 extending from the shoe to the servo rod having adjustment means 356 so that, with a given depth of cant, motion of the upper roll mount can be adjusted so as to vary the pressure exerted by the upper roll against the cant.

5. Structure as defined in claim 4, the edger including an output roll pair having a lower roll with an upper surface 325 coplanar of the horizontal plane containing the support surface 329, 'and an upper roll 326 mounted, generally as described with reference to the upper infeed roll on an arm 367, opposite ends of which are joumalled respectively in a fixed shaft and in the mount, and means 361 to transfer motion of the upper infeed roll to the upper outfeed roll so that the upper outfeed roll is also spaced from the lower outfeed roll according to the depth of the cant.

6. Structure as defined in claim 5, wherein the transfer means includes; an infeed pulley 362, an outfeed pulley 363, a cable 364 passing over the pulleys, one end of the cable being connected 365 to an extension of the arm 341 to which the hydraulic means is journalled as aforesaid, and an opposite end of the cable being connected to the outfeed roll arm 367. 

1. In an edger having a feed roll pair feeding a cant to a circular saw, the feed roll pair including an upper and a lower roll, sensor means responsive to depth of a cant about to enter between the upper and lower rolls constructed and arranged to set spacing between the rolls by accordance with the depth of the cant, the sensor including a. a shoe 321 normally urged towards an infeed support means 329 and having an outer end hinged to a frame of the edger so that passage of the cant beneath the shoe swings the shoe about the hinge, b. hydraulic means 343 having an upper end 346 journalled in a fixed bracket 347 and a servo rod 351, c. a link 350 extending from the shoe to the servo rod, d. a lower end 344 of the hydraulic means being journalled in an arm 341 the arm having an outer end journalled on a fixed shaft 342 and an inner end journalled to a mount 334 of the upper roll, the lower roll being mounted rotatable of a fixed axis positioned so that an upper surface of the roll is coplanar of the horizontal plane containing the support surface 329 constructed and arranged so that passage of the cant beneath the shoe, swinging the shoe as aforesaid, moves the servo rod activating the hydraulic means retracting the lower end so as to space the upper roll from the lower roll a distance according to the depth of the cant.
 2. Structure as defined in claim 1, the shoe having an upturned inner end 322 and being inclined at an acute angle to an upper surface of the cant so as to facilitate entry of the cant beneath the shoe.
 3. Structure as defined in claim 2, the upper roll mount including a compression spring 336 urging the upper roll downwards against the cant with a pressure determined by the depth of the cant.
 4. Structure as defined in claim 3, the link 350 extending from the shoe to the servo rod having adjustment means 356 so that, with a given depth of cant, motion of the upper roll mount can be adjusted so as to vary the pressure exerted by the upper roll against the cant.
 5. Structure as defined in claim 4, the edger including an output roll pair having a lower roll with an upper surface 325 coplanar of the horizontal plane containing the support surface 329, and an upper roll 326 mounted, generally as described with reference to the upper infeed roll on an arm 367, opposite ends of which are journalled respectively in a fixed shaft and in the mount, and means 361 to transfer motion of the upper infeed roLl to the upper outfeed roll so that the upper outfeed roll is also spaced from the lower outfeed roll according to the depth of the cant.
 6. Structure as defined in claim 5, wherein the transfer means includes; an infeed pulley 362, an outfeed pulley 363, a cable 364 passing over the pulleys, one end of the cable being connected 365 to an extension of the arm 341 to which the hydraulic means is journalled as aforesaid, and an opposite end of the cable being connected to the outfeed roll arm
 367. 